Pakal Votan Tomb Lid: The Serpent Bar

The Serpent Bar,
also known as the Bicephalic Bar, the Double-headed Serpent Bar, and
the Ceremonial Bar, is a sceptre carried in the arms of the rulers,
usually held against their chests. To hold the Bar, Maya rulers put
their hands in a formal gesture with their wrists back to back and their
thumbs turned outward.(source: A Forest of Kings:The Untold Story of the Ancient Maya)

A two-headed serpent bar (the Maya symbol of royalty) is wrapped around
branches of the Tree of the World. The body is made of jade segments,
again conferring special value on the serpent. The heads on each end of
the bar correspond, piece by piece, to the skeletal dragons
at the opening to the Underworld. Whereas the Underworld is like a
skeleton, Earth, represented by the serpent, has flesh.(Source www.delange.org/PalenqueTomb/PalenqueTomb.htm)